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排序方式: 共有272条查询结果,搜索用时 15 毫秒
121.
Gang Wang Naisa Chandrasekhar Bishnu P. Biswal Daniel Becker Silvia Paasch Eike Brunner Matthew Addicoat Minghao Yu Reinhard Berger Xinliang Feng 《Advanced materials (Deerfield Beach, Fla.)》2019,31(28)
Organic electrode materials are of long‐standing interest for next‐generation sustainable lithium‐ion batteries (LIBs). As a promising cathode candidate, imide compounds have attracted extensive attention due to their low cost, high theoretical capacity, high working voltage, and fast redox reaction. However, the redox active site utilization of imide electrodes remains challenging for them to fulfill their potential applications. Herein, the synthesis of a highly stable, crystalline 2D polyarylimide (2D‐PAI) integrated with carbon nanotube (CNT) is demonstrated for the use as cathode material in LIBs. The synthesized polyarylimide hybrid (2D‐PAI@CNT) is featured with abundant π‐conjugated redox‐active naphthalene diimide units, a robust cyclic imide linkage, high surface area, and well‐defined accessible pores, which render the efficient utilization of redox active sites (82.9%), excellent structural stability, and fast ion diffusion. As a consequence, high rate capability and ultrastable cycle stability (100% capacity retention after 8000 cycles) are achieved in the 2D‐PAI@CNT cathode, which far exceeds the state‐of‐the‐art polyimide electrodes. This work may inspire the development of novel organic electrodes for sustainable and durable rechargeable batteries. 相似文献
122.
Interpenetrating polymer networks based on carboxylated nitrile rubber and poly(alkyl methacrylate)s
N. R. Manoj D. Ratna V. Dalvi L. Chandrasekhar M. Patri B. C. Chakraborty P. C. Deb 《Polymer Engineering and Science》2002,42(8):1748-1755
A series of interpenetrating polymer networks (IPNs) based on carboxylated nitrile rubber (XNBR) and poly(alkyl methacrylate)s such as poly(methyl methacrylate) (PMMA), poly(ethyl methacrylate) (PEMA) and poly(butyl methacrylate) (PBuMA) were synthesized. The compositions of the IPNs were also varied by changing the swelling time of the rubber in the methacrylate monomer. The tensile and dynamic mechanical properties of the IPNs were studied. The dynamic mechanical properties in the range of 1–105 Hz were obtained by the time‐temperature superposition of the data under multifrequency mode, which indicated high tanδ with good storage modulus in the entire frequency range. This indicates the suitability of these IPNs as vibration and acoustic dampers. 相似文献
123.
Sagarika Meher Dr. Chandrasekhar Reddy Gade Dr. Nagendra K. Sharma 《Chembiochem : a European journal of chemical biology》2023,24(4):e202200732
Tropolone is a non-benzenoid aromatic scaffold with unique photophysical and metal-chelating properties. Recently, it has been conjugated with DNA, and the photophysical properties of this conjugate have been explored. Tropolonyl-deoxyuridine (tr-dU) is a synthetic fluorescent DNA nucleoside analogue that exhibits pH-dependent emissions. However, its solvent-dependent fluorescence properties are unexplored owing to its poor solubility in most organic solvents. It would be interesting to incorporate it into DNA primer enzymatically. This report describes the solvent-dependent fluorescence properties of the silyl-derivative, and enzymatic incorporation of its triphosphate analogue. For practical use, its cell-internalization and cytotoxicity are also explored. tr-dU nucleoside was found to be a potential analogue to design DNA probes and can be explored for various therapeutic applications in the future. 相似文献
124.
M. Chandrasekhar D.V. Sunitha N. Dhananjaya H. Nagabhushana S.C. Sharma B.M. Nagabhushana C. Shivakumara R.P.S. Chakradhar 《Materials Research Bulletin》2012,47(8):2085-2094
Hexagonal Dy(OH)3 and cubic Dy2O3 nanorods were prepared by hydrothermal method. Dy(OH)3 nanorods was directly obtained at 180 °C for 20 h after hydrothermal treatment whereas subsequently heat treatment at 750 °C for 2 h gives pure cubic Dy2O3. SEM micrographs reveal that needle shaped rods with different sizes were observed in both the phases. TEM results also confirm this. The TL response of hexagonal Dy(OH)3 and cubic Dy2O3 nanorods have been analyzed for γ-irradiation over a wide range of exposures (1–5 kGy). TL glow peak intensity increases with γ dose in both the phases. The activation energy (E), order of kinetics (b), and frequency factor (s) for both the phases have been determined using Chen's peak shape method. The simple glow curve shape, structure and linear response to γ-irradiation over a large span of exposures makes the cubic Dy2O3 as a useful dosimetric material to estimate high exposures of γ-rays. 相似文献
125.
We report selective tunnelling through a nanographene intermolecular tunnel junction achieved via scanning tunnelling microscope tip functionalization with hexa-peri-hexabenzocoronene (HBC) molecules. This leads to an offset in the alignment between the energy levels of the tip and the molecular assembly, resulting in the imaging of a variety of distinct charge density patterns in the HBC assembly, not attainable using a bare metallic tip. Different tunnelling channels can be selected by the application of an electric field in the tunnelling junction, which changes the condition of the HBC on the tip. Density functional theory-based calculations relate the imaged HBC patterns to the calculated molecular orbitals at certain energy levels. These patterns bear a close resemblance to the π-orbital states of the HBC molecule calculated at the relevant energy levels, mainly below the Fermi energy of HBC. This correlation demonstrates the ability of an HBC functionalized tip as regards accessing an energy range that is restricted to the usual operating bias range around the Fermi energy with a normal metallic tip at room temperature. Apart from relating to molecular orbitals, some patterns could also be described in association with the Clar aromatic sextet formula. Our observations may help pave the way towards the possibility of controlling charge transport between organic interfaces. 相似文献
126.
Rahul M. T. Chacko Sobi K. Raneesh B. Philip K. Annieta Kalarikkal Nandakumar Rouxel Didier Munirathinam Prabavathi Chandrasekhar Arunkumar 《Journal of Materials Science》2022,57(15):7653-7666
Journal of Materials Science - The composite approach is very effective in developing multiferroic systems with remarkable magnetoelectric coupling coefficients. In this work, P(VDF-HFP)-based... 相似文献
127.
S. Suryakumar K.P. Karunakaran Alain Bernard U. Chandrasekhar N. Raghavender Deepak Sharma 《Computer aided design》2011,(4):331-344
Hybrid Layered Manufacturing is a Rapid Manufacturing process in which the metallic object is built in layers using weld deposition. Each layer built through overlapping beads is face milled to remove the scales and scallops and ensure Z-accuracy. The formations of single beads and overlapping multiple beads are modeled in this paper. While the individual bead’s geometry is influenced by the size of the filler wire and the speeds of the wire and torch, the step over increment between the consecutive beads additionally comes into the picture for the multiple bead deposition. These models were validated experimentally. They are useful not only to predict the bead’s shape but also to optimize the three process parameters. 相似文献
128.
Organooxotin cages, clusters, and coordination polymers containing [Sn 2(mu-O)], [Sn 2(mu-OH)], [Sn 2(mu-O) 2], [Sn 2(mu-OH) 2], and [Sn 3(mu 3-O)(mu-OR) 3] building blocks have been assembled by the reactions of organotin precursors with phosphonic, phosphinic, carboxylic, or sulfonic acids. Various synthetic methodologies including Sn-C bond cleavage reactions and solventless procedures have been utilized to generate several nanodimensional organostannoxane assemblies. The synthesis, structure, and structural interrelationship of these diverse organostannoxane compounds are discussed. The synthetic knowledge gained to prepare specific organostannoxane structural forms in high yields has been utilized for the construction of dendrimer-like molecules. These contain a central stannoxane core and a functional periphery. The functional periphery can be readily modulated to assemble photoactive, electroactive, or multisite coordinating molecules. The synthesis, structure, and potential uses of these compounds are discussed. 相似文献
129.
Vadapalli Chandrasekhar Venkatasubbaiah Krishnan Palani Sasikumar Varanasi S. R. Murthy 《Journal of Inorganic and Organometallic Polymers and Materials》2007,17(2):439-446
Cross-linked polysilanes were prepared by the co-polymerization of Me2SiCl2 or PhMeSiCl2 with varying amounts of divinylbenzene (2–15% by weight) using molten sodium as the dehalogenating agent. All the cross-linked
polysilanes were stable to air and could be processed thermally for conversion to silicon carbide. Polymers containing from
5–15% of the cross-linking agent underwent a uniform shrinkage during thermal treatment (1500 °C) to afford β-SiC in good
yields. The ceramic was characterized by a variety of techniques including Raman and infrared spectroscopy, powder XRD, as
well as Scanning Electron Microscopy (SEM).
Dedicated to Prof. C. W. Allen in recognition of his outstanding contributions to inorganic polymers.
Deceased in a tragic car accident in July 2004. 相似文献
130.